Coleman retired the final 21 batters en route to his second career complete game Tuesday as the Iowa Cubs edged the Round Rock Express, 2-1, in the first game of a doubleheader.

The 22-year-old right-hander was coming off back-to-back losses in which he surrendered 11 earned runs over nine innings. And he got off to a less-than-auspicious start against Round Rock, allowing a leadoff single to Brian Bogusevic and a double to Oswaldo Navarro.

Navarro, however, turned out to be the Express' last baserunner. After former first-round pick Jason Castro was retired on a comebacker, Chris Johnson lifted a sacrifice fly to produce Round Rock's lone run.

Coleman (6-5) allowed only four more balls out of the infield. He recorded a career-high eight strikeouts and finished off his first complete game since May 28, 2009, when he absorbed a seven-inning loss for Double-A Tennessee.

The son of former Major League pitcher and current Lakeland Flying Tigers pitching coach Joe Coleman was a Southern League midseason All-Star last year. He ended up 14-6 with a 3.68 ERA, shared the league lead in wins and finished seventh in ERA.

Coleman's performance came one night after Brett Jackson -- Chicago's first-round pick in last year's Draft -- hit a walk-off homer in the 11th inning to complete the cycle for Class A Advanced Daytona.